I am New to Vestacp. I have Installed the Control Panel 3 days back and I am configuring my sites everything working fine but Suddenly I am not able to upload any file in FTP showing "553 Could not create file." Due to this I can't do any work, the Hosting company doesn't provide any help So please help me.
I have Installed it on Centos 64 bit.

Do you have write permissions (as this user or otherwise) on the remote system? If no, this might be the reason for error.

Either change the ownership of the folder or change the permissions....
If it is your account in the remote system, and you made the destination folder as someone else (Root for example) there may not be any write permissions for the proper user.